Cabinet freezer energy-saving temperature control method and system based on double inverter compressors and medium

Abstract

The invention discloses a cabinet freezer energy-saving temperature control method and system based on double inverter compressors and a medium, and belongs to the technical field of refrigeration control. The method comprises the steps that after a system is powered on, a compressor preheating and peak shifting start-stop process is executed, and current impact is avoided; when the temperature in the box reaches a set value, a single-compressor low-rotating-speed stable operation mode is switched to reduce energy consumption; in the mode, the rotating speed of the host is dynamically adjusted or the slave is started and stopped through a multi-stage compensation strategy based on temperature threshold judgment, so that the temperature is kept stable; meanwhile, the state of the compressor is monitored in real time, and fault diagnosis and redundancy control are executed; through master-slave cooperation and stepped adjustment, balance of rapid cooling and fine energy saving is achieved, system energy consumption is remarkably reduced, and temperature control precision and operation reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refrigeration control, and particularly relates to a freezing cabinet energy-saving temperature control method and system based on a double-frequency compressor and a medium. BACKGROUND

[0002] Freezing equipment, especially large-capacity freezing cabinets, cold stores and commercial refrigeration equipment, as typical high-energy-consumption electrical appliances, accounts for a significant proportion of commercial and industrial electricity consumption. Under the dual pressures of global energy shortage and environmental protection, reducing the operating energy consumption of such equipment has become the core issue of industry development. Research shows that more than 95% of the energy consumption of freezing equipment is concentrated in the operation control of its refrigeration core, the compressor, so the optimization of the compressor control strategy is the key breakthrough to realize equipment energy saving. In the prior art, for freezing equipment equipped with double compressors, the main energy-saving temperature control methods mainly exist in the following two typical schemes: Variable frequency control scheme based on traditional PID algorithm: This scheme dynamically adjusts the compressor speed through the PID (proportional-integral-derivative) controller to track the preset temperature curve. Its advantage is that the control theory is mature, and under proper parameter setting, relatively stable temperature control can be achieved. However, this scheme has significant disadvantages: first, the PID control performance is heavily dependent on the setting of initial parameters, and usually requires experienced technicians to conduct long-term on-site debugging, which is time-consuming and costly; second, when facing a refrigeration system with large inertia and strong hysteresis, the PID algorithm is prone to overshoot or oscillation, resulting in an increased temperature fluctuation range and unnecessary energy consumption during adjustment. Simply relying on the PID algorithm is difficult to achieve energy optimization while ensuring accuracy. Double-compressor simultaneous start-stop or simple master-slave control scheme: To meet the large cooling capacity demand, existing double-compressor systems mostly use "one drives two" or simultaneous start-stop control logic. That is, two compressors are started and stopped simultaneously, or a fixed running time ratio (start-stop ratio) is set. This way, the control logic is simple and highly reliable, but the energy efficiency is low. The problem is that: on the one hand, simultaneous start-stop of double machines will produce a huge instantaneous current shock, which is not good for the power grid and the service life of the compressor; on the other hand, regardless of the load demand, the double machines are always running at high power synchronously, and cannot output power in a fine-grained manner according to the actual cooling demand, resulting in a large amount of energy wasted on "overcooling". In addition, the sudden switch from full-load operation to complete stop will cause a sharp shock in the pressure and temperature of the refrigeration system, which is not conducive to the stable maintenance of the temperature in the box and affects the quality of stored goods. While existing technologies have improved energy efficiency and control flexibility to some extent through frequency conversion and dual-machine configurations, they still generally suffer from problems such as complex commissioning, incomplete energy consumption optimization, large temperature fluctuations, and significant oscillations during system switching. Especially in application scenarios that require both extremely low energy consumption operation and high-precision temperature control, existing solutions struggle to achieve the optimal balance between the two. Summary of the Invention

[0003] The main objective of this invention is to provide an energy-saving temperature control method, system, and medium for freezers based on a dual-frequency conversion compressor, aiming to solve existing technical problems.

[0004] To achieve the above objectives, this invention provides an energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor, comprising the following steps: S1: During the initial power-on phase of the system, the compressor preheating and off-peak start-up and shutdown process is executed; S2: After the internal temperature reaches the set temperature Tset for the first time, the system enters a single-compressor stabilization phase, shutting down one of the compressors acting as a slave compressor, while the other compressor acting as the master compressor maintains operation at the lowest operating speed Fmin; S3: During the single-compressor stabilization phase, based on changes in the internal temperature, the speed of the master compressor is adjusted or the start-up and shutdown of the slave compressors are controlled through a multi-level compensation strategy to maintain the internal temperature within the target range; S4: The operating status of the compressors is monitored in real time, and when a single compressor is determined to be faulty, a fault handling strategy is executed.

[0005] Further, step S1 includes; S11: Preheat the capillary tube containing the compressor; S12: After preheating, the main compressor is linearly started from its stop speed Fstop to its maximum speed Fmax with a fixed step size V; after a first time delay t1, the slave compressor is started in the same way; S13: When the temperature inside the chamber drops to the off-peak shutdown temperature node Tpv, the slave compressor is linearly reduced from its current speed to the minimum operating speed Fmin with the fixed step size V, and this speed is maintained until the temperature inside the chamber reaches the set temperature Tset and then the slave compressor is shut down.

[0006] Furthermore, the fixed step size V is linearly related to the temperature sampling period T, satisfying V=K×T, where K is a constant in r; the minimum operating speed Fmin is calculated in conjunction with the ambient temperature T_ambient temperature and the set temperature T_set, satisfying Fmin=f×K1×K2, where K1 is the ambient temperature coefficient and satisfies K1=T_set / T_set, K2 is the temperature coefficient and satisfies K2=T_ambient temperature / T__ambient temperature, and f is a constant 1600r / min; The peak-shaving shutdown temperature node Tpv is based on the formula. The calculation determines that Tset is the set temperature in °C; T_ambient temperature is the current ambient temperature of the freezer in °C; and T_correction is a fixed constant of 1.7 °C.

[0007] Furthermore, the multi-level compensation strategy in step S3 includes: S31.1: First compensation factor: When the temperature inside the chamber is greater than the first threshold Tset0, the slave compressor is started and the system switches to dual-machine operation mode. Tset0 is determined based on the upper limit of the temperature inside the chamber that the master compressor can maintain when running at Fmin speed. S31.2: Second compensation factor: When the temperature inside the chamber is ≤ Tset0 and > the second threshold Tset1, the main compressor is controlled to linearly increase from Fmin to Fmax with a fixed step size V; S31.3: Third compensation factor: If the internal temperature is ≤ Tset1 during multiple consecutive sampling cycles and the internal temperature is continuously rising while the compressor is running, the operating speed of the main compressor will be gradually increased according to the preset rules.

[0008] Furthermore, the execution of the third compensation factor includes; In each temperature sampling cycle, it is determined whether the current temperature inside the chamber is greater than the temperature of the previous cycle and whether the compressor speed is greater than the shutdown speed Fstop. If this condition continues for a second predetermined time, the compensation coefficient n is incremented by 1, and the operating speed of the main compressor is adjusted to Fmin + m × n, where m is a fixed compensation speed. When the temperature inside the chamber drops to the low-temperature protection point T for freezing or the conditions for starting the slave compressor are met, the compensation coefficient n is set to zero.

[0009] Furthermore, the fault determination in step S4 includes: S41.1: Dual compressor operation fault determination: When the continuous running time of both compressors exceeds the third predetermined time, and the absolute difference in the outer wall temperature of the exhaust port of the two compressors is greater than the current ambient temperature T, the compressor with the lower temperature is determined to be faulty; S41.2: Single compressor operation fault determination: When only a single compressor is running at the maximum speed Fmax, and the temperature inside the chamber does not decrease or rise within the third predetermined time, the compressor is determined to be faulty.

[0010] Furthermore, the fault handling strategy is as follows: When a single compressor is determined to be faulty, the startup logic and the first compensation factor logic of the slave compressor are disabled, the non-faulty compressor is operated as the master compressor, and its speed is adjusted only according to the second compensation factor logic, while triggering a fault alarm.

[0011] Furthermore, the method is applied in the refrigeration systems of freezers, refrigerators, cold storage facilities, or air conditioners.

[0012] A computer-readable storage medium having a computer program stored thereon, characterized in that: when the computer program is executed by a processor, it implements the steps of the above-described energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor.

[0013] A freezer energy-saving temperature control system based on dual variable frequency compressors includes at least two variable frequency compressors, a temperature sensor, and a controller, wherein the controller is configured to execute the freezer energy-saving temperature control method based on dual variable frequency compressors as described above.

[0014] The beneficial effects of this invention are reflected in: This invention employs the core strategies of "staggered start-up and shutdown" and "single compressor low-speed stabilization." After the system reaches the set temperature, it prioritizes maintaining operation at the minimum necessary speed of a single compressor, thus avoiding energy waste caused by long-term high-load operation of dual compressors or simultaneous start-up and shutdown.

[0015] The staggered shutdown strategy of this invention allows the compressor to smoothly decelerate and stop, avoiding sudden withdrawal of cooling capacity and significantly reducing temperature fluctuations when switching from dual-unit operation to single-unit operation. The multi-level compensation strategy can intelligently and gradually adjust the compressor speed or start / stop the slave unit based on minute temperature change trends during the single-unit stabilization phase, precisely controlling the temperature fluctuation range within the cabinet to a smaller range than traditional solutions, thus better meeting the high temperature stability requirements of stored items.

[0016] This invention's off-peak start-up strategy effectively avoids the peak starting current of the two compressors, reducing the impact of instantaneous current on the power grid and compressor drive circuit, thus improving the safety of the electrical system and extending the compressor's lifespan. The built-in compressor fault diagnosis and handling logic can promptly identify individual unit anomalies and enter a safe operating mode while ensuring basic cooling functions, improving the system's fault tolerance and overall reliability, and reducing the risk of downtime due to compressor failure.

[0017] In the initial power-on phase, this invention adopts a high-power strategy similar to the traditional simultaneous power-on and simultaneous power-off strategy, combined with a preheating function to prevent ice blockage, ensuring that the system can quickly cool down from the ambient temperature to the set temperature range, shortening the cooling time and improving the efficiency of equipment use. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the operation of a dual compressor in the prior art of this invention; Figure 2 This is a schematic diagram of the energy-saving temperature control method of step adjustment of the control curve according to the present invention; Figure 3 This is a schematic diagram of the refrigeration system structure of the dual-frequency conversion compressor freezer of the present invention; Figure 4 This is a schematic diagram of the operation of the dual compressors of the present invention; Figure 5 This invention is equipped with Tpv, T ambient temperature, and Tset mixing curves. Figure 4 Refer to the diagram. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention discloses an energy-saving temperature control method based on a step adjustment control curve, which can be applied to applications such as... Figure 3 The illustrated dual-frequency inverter compressor freezer refrigeration system mainly includes: a cabinet, two inverter compressors (defined as main compressor 1 and slave compressor 2 in this embodiment), a condenser 3, an evaporator 7, capillary tubes 6A / 6B, heat exchangers 5A / 5b, a dryer filter 4A / 4B, temperature sensors (for detecting the internal temperature Tin and ambient temperature Tamb), and a core controller (such as a PLC or microprocessor). The controller is electrically connected to the drive circuits of the two compressors and the temperature sensors, and is programmed to execute the following methods.

[0021] Example 1: This example provides a complete control method flow, such as... Figure 2 As shown, the specific steps are as follows: Step S1: System initialization and preheating staggered start / stop. After the system is powered on, initialization is performed first. The controller obtains the current chamber temperature Tin, ambient temperature Tamb, and user-set temperature Tset.

[0022] Preheating: The controller controls the capillary auxiliary heating device in the circuit containing compressors 1 and 2 to work for a period of time (e.g., 3-5 minutes) to eliminate any possible ice blockage and ensure cooling efficiency.

[0023] Off-peak start-up: After preheating, the controller controls the main compressor 1 to start from its stop speed Fstop (900 r / min in this embodiment), and linearly increase its speed every 2 seconds (i.e., sampling period T) with a fixed step size V = 100 r / min until it reaches its maximum allowable speed Fmax (4500 r / min in this embodiment). After the main compressor 1 has been running stably for 5 minutes (i.e., off-peak time t1), the controller starts the slave compressor 2 with the same step size V and method. This process ensures that the peak starting currents of the two compressors are staggered in time. The fixed step size V is linearly related to the temperature sampling period T, satisfying V = K × T, where K is a constant in r, and in this example K = 10 r.

[0024] Peak-shifting shutdown: When the internal temperature Tin drops to the preset peak-shifting shutdown node temperature Tpv, the controller controls compressor 2 to linearly decrease in speed by step V to the minimum operating speed Fmin, and maintains this speed until Tin reaches Tset, at which point compressor 2 is completely shut down. Fmin is calculated using the formula Fmin = f × K1 × K2, where K1 is the ambient temperature coefficient satisfying K1 = Tset / T_set, T_set is the reference temperature related to Tset, K2 is the temperature coefficient satisfying K2 = T_ambient temperature / T_ambient temperature, T_ambient temperature is the reference temperature related to T_ambient temperature, and f is a constant 1600 r / min, constrained within the range of [1600, 4500] r / min. Tpv is determined by an experimentally calibrated formula based on system volume, number of compressors, and other parameters. Where Tset is the set temperature in °C; T_ambient temperature is the current ambient temperature of the freezer in °C; and T_correction is a fixed constant of 1.7 °C.

[0025] Step S2: Single compressor low-speed stabilization. After compressor 2 is shut down, the system enters the single compressor stabilization phase. The main compressor 1 continues to operate at the calculated Fmin speed to maintain the internal temperature near Tset with the minimum required cooling capacity, thereby achieving basic energy savings.

[0026] Step S3: Multi-level intelligent compensation control. During the single-unit stabilization phase, to cope with load changes and prevent temperature exceedances, the controller performs three levels of compensation. Compensation factor 1: Set the first temperature threshold Tset0 = Tset + 2℃. If Tin > Tset0, it indicates that the cooling capacity of a single unit is insufficient. Then, compressor 2 is immediately started, and the system briefly returns to the dual-unit high-power operation mode (executes the staggered start-stop logic similar to step S100) until the temperature drops, and then enters single-unit stabilization mode again.

[0027] Compensation factor 2: Set the second temperature threshold Tset1 = Tset + 0.6℃. If Tin ≤ Tset0 and Tin > Tset1, and the current speed of the main compressor 1 is Fmin, the controller controls the main compressor 1 to linearly increase its speed from Fmin to Fmax in steps V to enhance the cooling capacity and prevent the temperature from continuing to rise to Tset0.

[0028] Compensation Factor 3: Within the range Tin ≤ Tset1, the system continuously monitors the temperature change trend. If, for 5 consecutive minutes (300 seconds), the current temperature in each sampling cycle (2 seconds) is higher than the temperature of the previous cycle, and the compressor is running, then the temperature rise trend is considered to be ongoing. At this time, the controller increments the compensation coefficient n by 1 (initially 0) and temporarily adjusts the speed of the main compressor 1 to Fmin + m × n, where m = 100 r / min, until the speed triggers compensation factor 2 or the temperature drops to the low-temperature protection point Tfreeze (set to Tset-3℃ in this embodiment). When other compensations are triggered or Tfreeze is reached, n is reset to zero.

[0029] Step S4: Fault Diagnosis and Handling. The controller monitors the compressor's operating status in real time and determines the fault: Dual-machine fault diagnosis: If both compressors have been running continuously for more than 30 minutes, and the absolute value of the difference between their exhaust port temperature sensor readings is greater than the current ambient temperature Tamb, then the compressor with the lower temperature is likely to be faulty.

[0030] Single-unit fault determination: If only the main compressor 1 runs at Fmax for more than 3 hours, and the internal temperature Tin does not decrease or continues to rise during this period, then the compressor is determined to be faulty.

[0031] Troubleshooting: Once a single unit malfunction is determined, the system will disable the faulty compressor and use only the other working compressor as the "master" compressor. It will also disable "compensation factor 1" (i.e., it will no longer attempt to start the other compressor) and rely solely on the logic of compensation factor 2 to adjust the speed of the only working compressor to maintain basic cooling function. At the same time, it will trigger an audible and visual alarm to indicate that maintenance is required.

[0032] Following the steps described above, the method of this embodiment was tested on a 580L freezer. Figure 4 and Figure 5 As shown in the comparative test curves, the system using the method of this invention (measured energy consumption 8.463 kW·h / 24h, temperature fluctuation ±0.8℃) has significantly improved energy consumption and temperature stability compared to the traditional simultaneous start-stop scheme (measured energy consumption 11.187 kW·h / 24h, temperature fluctuation ±0.95℃).

[0033] In another aspect, the present invention also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method described above.

[0034] In another aspect, the present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method described above.

[0035] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the dual-serial-bus-based switch matrix control systems described above.

[0036] It is understood that the systems, devices, and storage media provided in the embodiments of the present invention correspond to the methods provided in the embodiments of the present invention, and the explanations, examples, and beneficial effects of the relevant content can be referred to the corresponding parts of the above methods.

[0037] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor, characterized in that: Includes the following steps; S1: During the initial power-on phase of the system, the compressor preheating and off-peak start-up and shutdown process is executed; S2: After the internal temperature reaches the set temperature Tset for the first time, the single compressor stabilization phase is entered, one of the compressors acting as slave units is shut down, and the other compressor acting as master unit is kept running at the minimum operating speed Fmin. S3: During the single compressor stabilization phase, the main compressor speed is adjusted or the start-stop of the auxiliary compressor is controlled through a multi-level compensation strategy based on the temperature change inside the chamber, so as to maintain the temperature inside the chamber within the target range. S4: Monitor the compressor's operating status in real time, and execute the fault handling strategy when a single compressor is determined to be faulty.

2. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 1, characterized in that: Step S1 includes: S11: Preheat the capillary tube containing the compressor; S12: After preheating, the main compressor is linearly started from its stop speed Fstop to its maximum speed Fmax with a fixed step size V; after a first time delay t1, the slave compressor is started in the same way. S13: When the temperature inside the chamber drops to the off-peak shutdown temperature node Tpv, the slave compressor is linearly reduced from its current speed to the minimum operating speed Fmin with the fixed step size V, and this speed is maintained until the temperature inside the chamber reaches the set temperature Tset, after which the slave compressor is shut down.

3. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 2, characterized in that: The fixed step size V is linearly related to the temperature sampling period T, satisfying V=K×T, where K is a constant in r; the minimum operating speed Fmin is calculated in conjunction with the ambient temperature T_ambient temperature and the set temperature T_set, satisfying Fmin=f×K1×K2, where K1 is the ambient temperature coefficient and satisfies K1=T_set / T_set, K2 is the temperature coefficient and satisfies K2=T_ambient temperature / T__ambient temperature, and f is a constant 1600r / min; The peak-shaving shutdown temperature node Tpv is based on the formula. The calculation determines that Tset is the set temperature in °C; T_ambient temperature is the current ambient temperature of the freezer in °C; and T_correction is a fixed constant of 1.7 °C.

4. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 1, characterized in that: The multi-level compensation strategy in step S3 includes: S31.1: First compensation factor: When the temperature inside the chamber is greater than the first threshold Tset0, the slave compressor is started and the system switches to dual-machine operation mode. Tset0 is determined based on the upper limit of the temperature inside the chamber that the master compressor can maintain when running at Fmin speed. S31.2: Second compensation factor: When the temperature inside the chamber is ≤ Tset0 and > the second threshold Tset1, the main compressor is controlled to linearly increase from Fmin to Fmax with a fixed step size V; S31.3: Third compensation factor: If the internal temperature is ≤ Tset1 during multiple consecutive sampling cycles and the internal temperature is continuously rising while the compressor is running, the operating speed of the main compressor will be gradually increased according to the preset rules.

5. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 4, characterized in that: The execution of the third compensation factor includes: In each temperature sampling cycle, it is determined whether the current temperature inside the chamber is greater than the temperature of the previous cycle and whether the compressor speed is greater than the shutdown speed Fstop. If this condition continues for a second predetermined time, the compensation coefficient n is incremented by 1, and the operating speed of the main compressor is adjusted to Fmin + m × n, where m is a fixed compensation speed. When the temperature inside the chamber drops to the low-temperature protection point T for freezing or the conditions for starting the slave compressor are met, the compensation coefficient n is set to zero.

6. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 1, characterized in that: The fault determination in step S4 includes: S41.1: Dual compressor operation fault determination: When the continuous running time of both compressors exceeds the third predetermined time, and the absolute difference in the outer wall temperature of the exhaust port of the two compressors is greater than the current ambient temperature T, the compressor with the lower temperature is determined to be faulty; S41.2: Single compressor operation fault determination: When only a single compressor is running at the maximum speed Fmax, and the temperature inside the chamber does not decrease or rise within the third predetermined time, the compressor is determined to be faulty.

7. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to claim 6, characterized in that: The fault handling strategy is as follows: When a single compressor is determined to be faulty, the startup logic and the first compensation factor logic of the slave compressor are disabled, the non-faulty compressor is operated as the master compressor, and its speed is adjusted only according to the second compensation factor logic, while triggering a fault alarm.

8. The energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor according to any one of claims 1 to 7, characterized in that: The method is applied in the refrigeration systems of freezers, refrigerators, cold storage facilities, or air conditioners.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the energy-saving temperature control method for a freezer based on a dual-frequency conversion compressor as described in any one of claims 1 to 8.

10. An energy-saving temperature control system for a freezer based on dual variable frequency compressors, comprising at least two variable frequency compressors, a temperature sensor, and a controller, characterized in that: The controller is configured to perform the energy-saving temperature control method for freezers based on a dual-frequency conversion compressor as described in any one of claims 1 to 8.

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